Model calibration for mapping permafrost using Landsat-5 TM and RADARSAT-2 images

Permafrost is an important ground condition in high latitudes. Climate warming may lead to thickening of active layer, reducing permafrost thickness and extent, melting ground ice, causing ground subsidence and thermokarst erosions. In order to better map the distribution and dynamics of permafrost, there is a need to develop and test permafrost models that can be used with high spatial resolution remote sensing data. The purpose of this study is to calibrate the Northern Ecosystem Soil Temperature (NEST) model over the Victor Mine area located in the Hudson Bay Lowlands, Northern Ontario, Canada. The area is near the southern margin of permafrost region where permafrost exists only in isolated patches. We estimated and calibrated model input parameters using data from 1932 to 2012. The outputs were compared to field observations acquired between 2009 and 2012 at seven peat monitoring stations and two flux towers. Simulated soil temperatures show good agreement with observations at various depths for the different peatland types. The model shows the existence of permafrost only at palsa sites, which is in agreement with field observations. The calibrated model will be used to map permafrost over the whole area using remote sensing images.